Salesforce is bringing in the big guns for this one. The company has hired long-time Microsoft nemesis David Boies, founder of Boies, Schiller & Flexner LLP -- who represented the U.S. Department of Justice in its antitrust case against Microsoft last decade -- to make its case.

"We are reviewing Salesforce.com's filing, which we have just received. We remain confident about our position and will continue to press ahead with the complaint we initiated in the U.S. District Court for the Western District of Washington."